Sonic welding apparatus having fluid action aligning means

ABSTRACT

This application discloses an apparatus and method for sonically welding a plurality of thermoplastic members of flat plates. A sonic signal producing element or horn presses and imparts welding sonic signals to one of the thermoplastic members. A holding fixture holds one or more of such thermoplastic members. A base plate supports the holding fixture, and fluid action supporting means are provided between the holding fixture and the base plate. Such fluid action supporting means may include a plurality of solid actuated plungers to support said fixture. This construction equally distributes the main part of the force of the horn over the entire surface of the parts of the thermoplastic members to be welded together.

March 1972 w. J. BERLEYOUNG 3,649,421

SONIC WELDING APPARATUS HAVING FLUID ACTION ALIGNING MEANS OriginalFiled Sept. 18 1967 3 Sheets-Sheet l March 14, 1972 w. J. BERLEYOUNG3,649,421

SONIC WELDING APPARATUS HAVING FLUID ACTION ALIGNING MEANS OriginalFiled Sept. 18 1967 3 Sheets-Sheet 2 FIG-3 IOO 94 22 2 94 lOO H6 6INVENTOR. I30 WALTER J. BERLEYOUNG 84A 76A MWbm HIS ATTORNEYS March 14,1972 w. J. BERLEYOUNG 3,649,421

SONIC WELDING APPARATUS HAVING FLUID ACTION ALIGNING MEANS OriginalFiled Sept. 18 1967 3 Sheets-Sheet S 48 46 FIG-IO [26 INVENTOR. WALTERJ. BERLEYOUNG ms ATTORNEYS 16 Claims ABSTRACT OF THE DISCLOSURE Thisapplication discloses an apparatus and method for sonically welding aplurality of thermoplastic members or flat plates. A sonic signalproducing element or horn presses and imparts Welding sonic signals toone of the thermoplastic members. A holding fixture holds one or more ofsuch thermoplastic members. A base plate supports the holding fixture,and fluid action supporting means are provided between the holdingfixture and the base plate. Such fluid action supporting means mayinclude a plurality of fluid actuated plungers to support said fixture.This construction equally distributes the main part of the force of thehorn over the entire surface of the parts of the thermoplastic membersto be welded together.

This application is a divisional patent application of the co-pendingparent application, Ser. No. 668,508, filed Sept. 18, 1967, now Pat. No.3,506,510, and is assigned to the same assignee to whom the parentapplication is assigned.

This application is a continuation-in-part of copending application Ser.No. 643,716, filed June 5, 1967, for selfadjusting apparatus and methodfor sonic welding.

This invention relates to a fluid action support means and method forsonic welding.

One of the features of this invention includes sonic welding apparatusand method for sonically welding a plurality of thermoplastic members orrelatively flat plates by means of a signal producing element whichimparts welding sonic signals to one of such members or flat plates, aholding fixture to hold one or more of such members or flat plates, andfluid action support means automatically to distribute a main part ofthe force of said sonic signals to the parts of said members or flatplates to be sonically welded together. Such automatic means may includefluid action support means for said holding fixture automatically todistribute a main part of the force of said sonic signals to the partsof said thermoplastic members or flat plates to be sonically Weldedtogether.

Another feature of this invention includes a base member or base platehaving fluid flow means.

Another feature of this invention includes fluid plunger means betweensaid holding fixture and said base member or base plate.

Other features of this invention are apparent from this description, theappended claimed subject matter and/ or the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a sonic welding apparatus for weldingand performing a method of sonically welding various parts of aplurality of thermoplastic members or flat plates.

FIG. 2 is an enlarged top plan view of a portion of FIG. 1.

FIG. 3 is a vertical cross section, partly in elevation, taken along theline 33 of FIG. 2.

FIG. 3A is a vertical cross section of a feature that may be added.

FIG. 4 is a perspective exploded view of one of the fluid actuatedplungers.

FIG. 5 is a plan view somewhat similar to FIG. 2, but showing anotherembodiment.

FIG. 6 is a vertical cross section along line 6-6 of FIG. 5.

FIG. 7 is a view of part of FIG. 1 with a welding support die and aplurality of thermoplastic plates mounted on the holding fixture rockerplate.

FIG. 8 is an enlarged exploded perspective view of part of FIG. 7 takengenerally from line 8-8 of FIG. 7.

FIG. 9 is an enlarged perspective view of the thermoplastic plates takengenerally from line 99 of FIG. 7.

FIG. 10 is an enlarged cross section through the typical plates of FIG.8, substantially along the line 1010, and showing the two plates closelytogether before any welding action has taken place.

FIG. 11 is an enlarged diagrammatic cross section along the line 1111 ofFIG. 9.

FIG. 12 is an enlarged diagrammatic cross section along the line 12-12of FIG. 9.

Certain words may be used in this specification and claimed subjectmatter which indicate direction, relative position, and the like. Thesewords are used for the sake of brevity and clearness. However, it is tobe understood that such words are used only in connection with thevarious views of the drawings, and that, in actual use, the parts sodescribed, may have entirely different direction, relative position, andthe like. Examples of such words are vertical, horizontal, upper, lower,etc.

FIG. 1 shows a sonic Welding apparatus 20 which may be used forsonically welding a plurality of thermoplastic members or flat platesaccording to this invention. This apparatus 20 may be quickly adjustedto operate on a large number of different banks or assemblies of aplurality of thermoplastic members or fiat plates. Such apparatus 20 isadapted sonically to weld quickly a plurality of thermoplastic membersor flat plates to form a plurality of identical banks or assemblies ofsuch thermoplastic members or plates, or sonically to weld a pluralityof thermoplastic members or plates into a plurality of entirelydifierent banks or assemblies, as desired.

For example, it may be desired repeatedly to weld a plurality of membersor plates to form a plurality of identical banks or assemblies of suchmembers or plates relatively quickly. This apparatus 20 quickly adjustsitself, so that such members or plates are quickly received and quicklysonically welded together to form such identical banks or assemblies ofWelded flat members or plates. On the other hand, it may be desired toproduce a plurality of different banks or assemblies of such flatmembers or plates, in which case the apparatus may be quickly modifiedor adjusted repeatedly to produce such different banks or assemblies offlat members or plates in a manner more fully to be disclosed.

The apparatus 20 may include a signal producing element or horn 22having means 24 to press and impart welding sonic signals to onethermoplastic member or plate 26 of a plurality of relatively flatmembers or plates 26, 28, and the like, to weld certain parts of theplates 26 and 28 together.

Certain parts of the apparatus 20 may be purchased, for example, fromBranson Instruments, Inc., which has a place of business at Danbury,Conn, or from some other similar supplier of such equipment. Suchpurchased apparatus 20 may then be modified to have the form andoperation of this invention.

The parts of the apparatus 20 which may be purchased or obtained fromsuch suppliers may include a stand or pedestal 30 which supports thesonic welding horn 22, so that such horn may be moved vertically bysuitable hydraulic or pneumatic cylinders 32 which raise and lower asupporting platform construction 34 on posts 35.

The platform 34 carries a horn supporting shaft 36, a sonic power unit38, which may be connected to a power supply unit, not shown, but wellknown.

The horn 22 is readily secured to and readily removed from the shaft 36.The horn 22 may be tailored by the supplier in accordance with thedesign or request of the user to match the article to be contacted. Tooperate on the plates 26 and 28 such horn may be provided with arelatively large constant area under surface or face 24 which is adaptedto engage a large area of the upper plate 26 when the horn 22 is loweredinto sonic welding position. The plurality, or pair of plates 26 and 28,are placed together on top of the welding support die 40, FIGS. 7 and 8,which die has a raised portion 41, and then the horn is brought intowelding engagement with the top of the plate 26, and sonic signals areproduced in and by the horn 22 to produce the sonic welding operation tobe described.

The words sonic" and ultrasonic and derivatives thereof are intended tobe used interchangeably herein to describe vibrations of the charactersuitable for performing the welding operation of this invention. Forexample, typical frequencies may have a range of from 4,000 to 20,000vibrations per second, more or less.

The thermoplastic members or flat plates, such as 26 and 28, hereindisclosed, are merely illustrative of the many diiferent kinds ofthermoplastic plates or members that are capable of being sonicallywelded by this invention. For example, such plates may have one or morechannels 42 which may be covered and sealed by the under surface 44 ofthe plate 26. To accomplish this, one or more ridges 46 and 48, FIG. 10,may be formed to surround the channel 42, so that such ridges are meltedduring the sonic welding operation and are formed into sealing andholding bands 50, FIGS. 11 and 12, which seal the sides of the channels42 and hold the plates 26 and 28 together. However, this is merelyillustrative of the many local welds that may be made between the fiatmembers or plates.

If desired, suitable cones 52 may be added to plate 28 to seal togetherthe plates 26 and 28 at places where they are not sealed together by thebands 50. The cones 52 may be substantially of the same cross section asshown for the ridges 46 and 48. This also is merely illustrative ofother local welds to be produced.

The following details concerning the plates, channels, etc., are givenmerely to illustrate and give proper background of this invention.

The plates 26 and 28 may be made of thermoplastic material suitable forthe sonic welding operations herein described. Such thermoplasticmaterial may be readily selected by anyone skilled in the art. Forexample, the plates 26 and 28 may be injection molded, in suitablemolds, of Dupont Lexan plastic, or any of the many similar plasticmaterials available on the market and readily selected by those skilledin the art. The ridges 46 and 48 may be in the order of 60 degrees and90 degrees, as to the angle between their sides and may have a crosssection that forms an equilateral angle.

The plates 26 and 28 may be of any desired size, such as 2" wide alongthe edges. The channels 42 may be .031" wide and .031" deep, more orless. The outer, higher ridges 48 may be from .066" to .088" high, moreor less, and .120" between the two higher ridges 48, more or less. Thelower ridges 46 may be from .004" to .006" high, more or less, and maybe .082" between the two lower ridge tops. The thickness of the plates26 and 28 may be, as proportionally shown, with respect to the depth ofthe channel 42, or they may be of any other proper width, as desired.

The plate 26 may have an upward integral tube 54 which is connected tothe channel 42 and enters, and is not pressed, by the opening 56 in theface 24. The plate 26 may have two integral upward hook members 58,which are not to be Welded, and are not necessarily material to thisinvention, and which enter and are not pressed by the upward slots 60 inthe face 24. The plate 28 may have two integral downward tubes 62 and64, which are connected to the channel 42, and which enter and are notpressed by the openings 67 and 69 on the welding support die 40. Afterthe welding operation, the tube 54 may be sealed to the central part ofthe channel 42, as shown in FIG. 11, and the channel 42 may be connectedto the downward tube 62, as shown in FIG. 12, and to the tube 64, at theother end of the channel. In this manner air or other fluid may becaused to flow by and between the tubes 54, 62, 64, and any other tubesor openings desired. The channel 42 may have downwardly and upwardlydirected openings 66 and 68 at any desired places.

It is to be understood that all of these details in plates 26 and 28 aremerely illustrative, to show that such plates may be welded together forany purpose, to produce fluid flow passageways and the like with orwithout tubes or openings, as desired. Many other dilferent types ofplates may be used instead of the ones illustrated.

To produce the desired sonic welding action between the relatively flatmembers or plates 26 and 28 it is necessary that a relatively largesurface area contact be established between the upper surface of plate26 and face 24 or horn 22 to prevent any welding or melting actionbetween these surfaces. It is also necesary that a main part of theforce of the sonic signals from horn 24 be equally distributed andconcentrated at the relatively small areas of the ridges 46, 48 andcones 52 between the plates 26 and 28. Also a relatively large,unconcentrated area must be maintained between the raised mainly fiatface 70 of the welding support die 40 and the under surface of the plate28. This is provided by the very slightly raised wide area flat portions72 and 74 of the face 70. These portions 72 and 74 concentrate the mainpressing and welding action at the ridges 46, 48 and cones 52 betweenthe plates 26 and 28.

In order to make these channels, tubes, and the like, substantiallysealed between and in the plates, and to join the plates hereindisclosed with other plates, to form other assemblies or banks, it isnecessary that the face 24 of the horn 22 and the face 7 0 of thewelding support die 40 be parallel to each other during the sonicwelding operation within extremely close tolerances. According to thisinvention, this parallelism is automatically obtained every time thattwo or more plates are placed between the faces 24 and 70, repeatedly toproduce a plurality of identical banks or assemblies quickly, one afterthe other, without having to carefully shim the welding support die 40to obtain the parallelism, Also, according to this invention, it ispossible to quickly change the horn 22, and the supporting die 40, toreceive other and different thermoplastic members or plates, and to weldthem together to produce different banks or assemblies of flat membersor plates, and quickly to repeat production of such different blanks orassemblies as will become apparent. According to this invention, thearrangement is such that the faces 24 and 70, or similar faces of otherhorns and dies, will quickly become parallel automatically during eachsonic welding operation. Also the arrangement is such that otherdifierent horns, similar to horn 22, and other different support dies,similar to support die 40, may be quickly substituted to change theapparatus 20 to receive and sonically weld other different but somewhatsimilar banks or assemblies of such flat members or plates.

Thus means are provided automatically to distribute a main part of theforce of the mainly lateral sonic signals to the parts of the fiatmembers or plates to be sonically welded together. To this end the baseplate 76 is secured tightly on the stand 30 by any suitable means. Forexample, fastener bars 78 have their ends held respectively on the baseplate 76 and on two blocks 80, which rest on the stand 30. Thesefastener bars are held down by the screws 81, which are screwed intotapped holes in the stand 30. This construction securely holds the baseplate 76 on the stand 30.

A rocker plate 82 is part of a holding fixture 83, FIG. 7, to which theweld support die may be secured, as will be described. The weld supportdie 40 has holding means to hold one or more of the thermoplasticmembers or plates 26, 28, etc.

Fluid action support means are provided for holding such rocker plate 82of the holding fixture 83 in a manner automatically to distribute a mainpart of the force of the sonic signals from the horn 22 to the parts ofthe members or plates 26, 28, etc. so that such members or plates areproperly sonically welded.

Such fluid action support means may include fluid flow means in the basemember or plate 76. Such fluid flow means may be in the form of aplurality of plunger receiving openings 84 connected to a plurality offluid passageways 86 underneath such openings 84. Some of thesepassageways 86 have threaded or tapped openings 88 which extend to theside walls 90 of the base plate 76. The openings 88 may be closed bythreaded plugs 92. The passageways 86 may be drilled in the plate 76.The rocker plate 82 may be provided with plunger receiving openings 94.

A plurality of fluid actuated plungers or pins 96 may be inserted in theopenings 84 and 94 in a manner automatically to level the rocker plate82 and the entire holding fixture 83 with respect to the face 24 of thehorn 22.

Each of the plungers 96 has a relatively thick cylindrical main body 98and opposite narrower top and bottom cylindrical ends 100 and 102. Thetop ends 100 are received in openings 94 and the bottom ends 102 are received in openings 84. Flanges 103 at the ends of the main body 98, ofthe plunger 96 form limiting means to limit the entry of each plungerinto the respective openings 84 and 94.

The bottom ends 102 of the plungers 96 have grooves 104 to receiveflexible sealing O-rings 106 which yieldingly seal the ends 102 of theplungers in the openings 84 and prevent the flow of fluid upwardly outof the openings 84.

The base plate 76 and rocker plate '82 may be assembled together in anydesired manner. For example, the plate 82 may be inverted and then theends 100 of the plungers 96 may be inserted in the openings 94. Then theplate 76, without any liquid fluid in the passageways 86, may beinverted, and the now upwardly directed ends 102 of the plungers may beinserted in openings 84. Spacers, not shown, may be placed between theplates 76 and 82 to hold the plates substantially parallel and spacedapart substantially the distance shown in FIG. 3, with the ends 102 ofplungers 96 partly out of the openings 84. The plugs 92 previously havebeen tightly inserted in the threaded openings 88. Then if liquid fluidis to be used, such liquid fluid may be inserted through a now upwardlydirected filling opening 108 until all the fluid passageways 86, etc.,have been filled with liquid fluid and substantially all the air hasbeen displaced. Then a threaded sealing plug 110 may be inserted andsealed in the opening 108.

The plates 76 and 82 may then be held in spaced relation by any suitablemeans, such as by any suitable clamps, etc., until the plates 76 and 82have been installed on the stand 30 of FIG. 1.

Any other method of assembling the plates 76 and 82 may be used inaddition or alternatively to the above method of assembly.

The plates 76 and 82 may be used with gaseous or liquid fluid asdesired. Any one of the plugs 92 may be a fluid pressure supply plug,92A, having a central fluid flow opening 93, to which a gaseous orliquid fluid pressure supply pipe or a closing plug, not shown, may beconnected. The plates 76 and 82, FIG. 3A, may be provided with limitscrews 112 which limit the distance of separation of the two plates 76and 86 when fluid pressure is applied through opening 93.

Each screw 112 may be loosely received in an opening 114 in plate 82with an enlarged countersunk screwhead opening 116 to receive thescrewhead 118 of screw 114. The screw 112 may be screwed into the tappedopening 120 in plate 76. With this construction the plate 82 is limitedin its upward travel by the screwheads 118 when fluid pressure isapplied at fluid flow opening 93. However, the plate 82 can yield to thepressure applied by the horn 22 during welding operations.

The rocker plate 82 is provided with tapped openings 122 into whichscrews 124 of FIG. 7 may enter. The screws 124 are first inserted inopenings 126 in the welding support die 40 of FIGS. 7 and 8 and then arethreadedly inserted into the openings 122 of the rocker plate 82. Theopenings 126 have countersunk portions, not shown, to receivecountersunk screwheads of screws 124, not shown, but well known.

The pressure from the horn 22 upon the thermoplastic plates '26 and 28will be distributed down to the rocker plate 82 and will cause theplungers 96 to move upon the fluid support in openings 84, displacingthe fluid on the higher side of the rocker plate 82 and thereby forcingthe lower side upward until the pressure is equally distributed to allof the parts of the thermoplastic members or plates to be welded.

In the embodiment of FIGS. 5 and 6 the same effect is achieved using thesame previous general configuration in rocker plate 82A, base plate 76A,openings 84A, 94A and plungers 96A. The only difference is that, insteadof interconnecting the holes or openings 84A in the base plate 76A, theholes 84A are connected by means of respective conduits 130, 131, 132and 133 through respective restrictors 134, 135, 136 and 137 to apressurized source of fluid, such as a pump or compressor, through acommon conduit 138 which may be connected by a pipe 139 and valve 140 tosuch pump or compressor. The valve 140 may be used to connect anddisconnect the fluid pressure supply, as desired. A similar pump,compressor and valve may be provided for the pipe to be connected toplug 92A which was previously described.

The plates 82A and 76A may be provided with limit screws similar tolimit screws 112 of FIG. 3A, if desired.

It is thus to be seen that a sonic welding apparatus and method forsonically welding a plurality of thermoplastic members or flat plateshave been provided. The signal producing element 22 has a means, or face24, to press and impart welding sonic signals to one of the flat membersor plates, such as 26, of a plurality of flat members or plates 26, 28.A holding fixture is provided, including the support die 40 having means70 to hold one or more of the flat members or plates 26 and 28, andautomatic fluid action support means have been provided automatically todistribute a main part of the force of the sonic signals sonically toweld the parts of the members or fiat plates desired to be welded.

A new and useful apparatus and method are thus provided for sonicallywelding such plurality of thermoplastic members or relatively flatplates.

While the form of the invention now preferred has been disclosed, asrequired by statute, other forms may be provided, all coming within thescope of the claims which follow.

What is claimed is:

1. Sonic welding apparatus for sonically welding a plurality ofthermoplastic members comprising, a sonic signal producing elementhaving pressing and signal imparting means to press and impart weldingsonic signals to one of said members, a holding fixture having holdingmeans to hold one or more of said members, and fluid action supportmeans for said holding fixture automatically to distribute a main partof the force of said sonic signals to the parts of said members to besonically welded together by substantially universally aligning saidholding fixture relative to said signal producing element.

2. A welding apparatus according to claim 1, in which said thermoplasticmembers are thermoplastic flat plates, with said signal producingelement having a generally flat face to press and impart sonic signalsto one of said plates, with said holding fixture having a generally flatface to hold one or more of said plates, and with said fluid actionsupport means automatically causing said flat faces to be automaticallysubstantially parallel to each other while said plates are beingsonically welded together.

3. Sonic welding apparatus according to claim 1, with said fluid actionsupport means including a base member having fluid flow means forming apart of said fluid action support means.

4. Sonic welding apparatus according to claim 3, in which saidthermoplastic members are thermoplastic flat plates, with said signalproducing element having a gen erally flat face to press and impartsonic signals to one of said plates, and with said holding fixturehaving a fluid action supported generally flat face to hold one or moreof said plates.

5. Sonic welding apparatus according to claim 3 with said signalproducing element having a generally flat signal imparting face toengage said one of said members, and said holding fixture having agenerally flat holding face to hold said one or more of said members.

6. Sonic welding apparatus according to claim 5 with said fluid actionsupport means maintaining said faces substantially parallel to eachother.

7. Sonic welding apparatus according to claim 3 with said fluid actionsupport means including fluid plunger means between said holding fixtureand said base member.

8. Sonic welding apparatus according to claim 3 with said base memberhaving a plurality of plunger receiving openings, fluid passagewayinterconnecting means interconnecting said plunger receiving openings,and fluid actuated plungers in said openings and supporting said holdingfixture.

9. Sonic welding apparatus according to claim 8 with said passagewayinterconnecting means having fluid passageways in said base member.

10. Sonic welding apparatus according to claim 9 in which a plurality ofsaid passageways interconnect said plunger receiving openings in saidbase.

11. Sonic welding apparatus for sonically welding a plurality ofthermoplastic members comprising, a sonic signal producing elementhaving pressing and signal imparting means to press and impart weldingsonic signals to one of said members, a holding fixture having holdingmeans to hold one or more of said members, fluid action support meansfor said holding fixture automatically to distribute a main part of theforce of said sonic signals to the parts of said members to be sonicallywelded together, said fluid action support means including a base memberhaving fluid flow means forming a part of said tfluid action supportmeans, said base member having a plurality of plunger receivingopenings, fluid passageway in terconnecting means interconnecting saidplunger receiving openings, fluid actuated plungers in said openings andsupporting said holding fixture, said passageway interconnecting meanshaving fluid passageways in said base member, a plurality of saidpassageways interconnecting said plunger receiving openings in saidbase, at least one of said passageways interconnecting two of saidplunger receiving openings and having a tapped opening extending to aside of said base, and a threaded plug in said tapped opening.

12. Sonic welding apparatus for sonically welding a plurality ofthermoplastic members comprising, a sonic signal producing elementhaving pressing and signal imparting means to press and impart Weldingsonic signals to one of said members, a holding fixture having holdingmeans to hold one or more of said members, fluid action support meansfor said holding fixture automatically to distribute a main part of theforce of said sonic signals to the parts of said members to be sonicallyWelded together, said fluid action support means including a base memberhaving fluid flow means forming a part of said fluid action supportmeans, said base member having a plurality of plunger receivingopenings, fluid passageway interconnecting means interconnecting saidplunger receiving openings, and fluid actuated plungers in said openingsand supporting said holding fixture, each of said plungers having arelatively thick cylindrical main body with relatively narrowercylindrical plunger ends.

13. Sonic welding apparatus according to claim 12 in which one of saidplunger ends has a flexible seal sealingly engaging the side of arespective plunger receiving opening.

14. Sonic welding apparatus according to claim 3 said base member havinga plurality of plunger receiving openings, fluid actuated plungers insaid plunger receiving openings and a plurality of fluid passagewaysrespectively connected to said openings and extending out of said basemember and being interconnected to a common conduit outside said basemember.

15. Sonic welding apparatus according to claim 14 in which restrictorsare provided in said passageways between said plunger receiving openingsand said common conduit.

16. Sonic welding apparatus according to claim 1, in which said holdingfixture includes a rocker member having means to hold a support diemember having means to hold one or more of said thermoplastic members,and said fluid action support means supports said rocker member.

US. Cl. X.R. l56'73; 228l

